Fear...

Why does anyone fear? I think, maybe because they encounter something they're not used to, something unusual, different, new.
For example, we all have our own customized set of principles and when they're challenged, we become defensive. We prefer to think that we've got the best of the sets and are ever ready to even fight to prove that we're right. This belief system is what gains us respect from others and it'll be pathetic to doubt our own beliefs.
I remember that episode from Friends where Phoebe convinces Ross, who's a paleontologist with years of experience, that there is a teeny tiny possibility that his belief about evolution might be wrong. He loses the teeny tiny respect that she had for him.
Also, most of the guys are afraid of commitment because they don't wanna change the routine they have. They don't wanna add things like cleaning the room, remembering anniversaries, making rigid plans or even taking bath on a regular basis; nor do they wanna remove things like appreciating beauty whenever they wanna (you know what I mean), option of returning back home or not, making bodily noises without guilt, etc. from their current routine. Once they commit, their whole life will become what it was not (dictatorship will take over democracy).
I'm not afraid of change. A routine mostly bores me. Sometimes, I have fun fighting with my best of friends.
I'm just afraid of success (ya, i'm not used to it) because after success, there's nothing left to do, there's no more life to live.